Geminus (crater)
Encyclopedia
Geminus is a lunar
impact crater
that is located near the northeast limb of the visible Moon
. In this position the crater appears oval in shape due to foreshortening, but it is actually more nearly circular in form. Notable nearby craters include Messala
to the northeast, Bernoulli
due east, and Burckhardt
and Cleomedes
to the south.
The circular rim of Geminus contain a number of outward notches, particularly to the north and east. The crater ejecta is still visible in the rough surroundings beyond the rim, but any rays
deposited during the impact have long since been worn away by space weathering
. The inner wall is wide and extensively terraced, although these features are now somewhat muted due to impact erosion. There are no notable impacts on the interior floor, but there is a long, slender central ridge located at the mid-point and a pair of readily observed clefts.
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
that is located near the northeast limb of the visible Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
. In this position the crater appears oval in shape due to foreshortening, but it is actually more nearly circular in form. Notable nearby craters include Messala
Messala (crater)
Messala is a lunar crater of sufficient dimension to belong to the category of impact features known as walled plains. It is located in the northeastern part of the Moon, close enough to the rim to appear significantly foreshortened. Nearly attached to the northern rim is the crater Schumacher...
to the northeast, Bernoulli
Bernoulli (crater)
Bernoulli is a lunar impact crater that is located in the northeast part of the Moon. It lies to the south of the crater Messala, and east of Geminus....
due east, and Burckhardt
Burckhardt (crater)
Burckhardt is a lunar impact crater that is located in the northeast part of the Moon. It lies between the craters Geminus just to the north and Cleomedes to the south....
and Cleomedes
Cleomedes (crater)
Cleomedes is a prominent lunar crater located in the northeast part of the visible Moon, to the north of Mare Crisium. It is surrounded by rough ground with multiple crater impacts. The irregular crater Tralles intrudes into the northwest rim. To the east is Delmotte...
to the south.
The circular rim of Geminus contain a number of outward notches, particularly to the north and east. The crater ejecta is still visible in the rough surroundings beyond the rim, but any rays
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
deposited during the impact have long since been worn away by space weathering
Space weathering
Space weathering is a blanket term used for a number of processes that act on any body exposed to the harsh space environment. Airless bodies incur many weathering processes:* collisions of galactic cosmic rays and solar cosmic rays,* irradiation, implantation, and sputtering from solar wind...
. The inner wall is wide and extensively terraced, although these features are now somewhat muted due to impact erosion. There are no notable impacts on the interior floor, but there is a long, slender central ridge located at the mid-point and a pair of readily observed clefts.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Geminus.| Geminus | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 31.5° N | 51.8° E | 15 km |
| B | 34.2° N | 52.3° E | 10 km |
| C | 33.9° N | 58.7° E | 16 km |
| D | 30.6° N | 47.4° E | 16 km |
| E | 33.5° N | 48.5° E | 67 km |
| F | 32.1° N | 51.1° E | 22 km |
| G | 30.8° N | 48.6° E | 14 km |
| H | 31.6° N | 48.9° E | 15 km |
| M | 31.9° N | 48.5° E | 11 km |
| N | 31.4° N | 47.7° E | 24 km |
| W | 34.3° N | 47.4° E | 6 km |
| Z | 30.7° N | 46.7° E | 26 km |